Detection of analytes in bodily fluid samples is widely used for medicinal and other purposes. Applications include detection of pathogens, proteins, or other chemical compounds in blood, urine, bile, saliva, or other bodily fluids. Some example applications include drug screening, detection of disease, detection of a particular protein, and the like. By way of one particular example, detection of circulating tumor cells (CTCs) in human blood and lymph systems has the potential to aid clinical decision making in the treatment of cancer. The presence of CTCs may signify the onset of metastasis, indicate relapse, or may be used to monitor disease progression.
Present techniques and devices for the detection of CTCs have limits. Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a technique that is used in practice. This technique involves the analysis of RNA. The technique takes significant time and involves a number of steps requiring the expertise of technicians to conduct assays. With the requirement of such expertise comes the potential for technician error. Freezing, culturing, assaying, etc. in the RT-PCR technique take both time and expertise. Results are also not immediately available to a treating physician.
Laser flow cytometry also has the potential to analyze samples for CTCs. However, CTC detection is evolving research area and optimal detection techniques are still a work-in-process. The technique, when and if it is perfected, however, remains one that shares some of the drawback to RT-PCR, e.g., skilled technician involvement and delays in obtaining and interpreting results.
Powerful diagnostic tools permit rapid and accurate evaluation. Critical to the treatment of cancer is the early stage detection of the onset of metastasis or relapse, and the monitoring of disease progression and the response of the disease to an ongoing course or treatment. Having accurate information about metastasis can provide a treating physician with the opportunity to be more effective and address the particular phase of the disease indicated by the metastasis. Accurately and rapidly detecting the presence of CTCs has the potential to advance the state of cancer diagnosis and treatment.